Container with floating vent tube for micro-fluid applications

ABSTRACT

A consumable supply item for an imaging device holds an initial or refillable volume of fluid. An interior holds the fluid and users orient a housing to deplete the fluid in a direction of gravity. An air conduit tube fluidly connects to an air port to vent the interior to atmosphere. A float buoyantly supports the tube on a surface of the volume of fluid. It suspends a terminal opening of the tube above the fluid so that as the volume of fluid depletes in the interior over time, or an orientation of the housing is altered during handling, the terminal opening is maintained above the surface of the volume of fluid. Fluid leakage is minimized during transport and manipulation.

FIELD OF THE INVENTION

The present invention relates to micro-fluid applications, such asinkjet printing. The invention relates further to supply item containersholding fluid, but overcoming leakage during times of transportation andabnormal orientation. Floating vent tubes facilitate the embodiments.

BACKGROUND

The art of printing images with micro-fluid technology is relativelywell known. A (semi)permanent ejection head has access to a local orremote supply of fluid. The fluid ejects from an ejection zone to aprint media in a pattern of pixels corresponding to images beingprinted.

Upon fluid ejection, containers holding fluid undergo pressureincreases. They are vented to atmosphere to equalize the pressure in avariety of ways. Some containers define tortuous paths in body walls toslowly vent air inside. Others have air vent ports that interface withcorresponding ports in imaging devices which, in turn, connect tosources of atmosphere. In either, vents provide avenues of fluid leakagefrom the containers during times of transport, storage, handling and/ormanipulation. To prevent leakage, labels/stickers are used to coverpaths and caps are plugged into ports that users remove before use. Withthe latter, however, vent ports are typically located above fluid levelsin the container during normal orientation. When imaging devices aremoved or suffer abnormal orientation, fluid can exit directly from thevent port causing spillage and endangering hardware. Leakage can alsooccur outside the imaging device when users handle containers after capremoval.

A need exists in the art to prevent fluid leakage from containers duringtimes of handling or abnormal orientation. The need extends not only toeconomical solutions, but to simplicity. Solutions should alsocontemplate the diversity of locations in which vent ports can be placedon containers. Additional benefits and alternatives are also sought.

SUMMARY

The above-mentioned and other problems become solved with containershaving floating vent tubes for micro-fluid applications. A consumablesupply item for an imaging device holds an initial or refillable volumeof fluid. A housing defines an interior to hold the fluid and locatesfluid exit and air vent ports. Users orient the housing to deplete thefluid in a direction of gravity. An air conduit tube fluidly connects tothe air vent port to vent the interior of the housing with air fromoutside the housing. A float is buoyantly positioned on a surface of thevolume of fluid. It connects to the air conduit tube to suspend aterminal opening of the tube above the fluid so that as the volume offluid depletes in the interior over time or an orientation of thehousing is altered during handling, the terminal opening is maintainedabove the surface of the volume of fluid. Fluid leakage is minimizedduring handling and transport. Relationships are noted between the tubeand the float as well as locations of the ports on the housing. Ahydrophobic membrane defines still other embodiments.

These and other embodiments are set forth in the description below.Their advantages and features will become readily apparent to skilledartisans. The claims set forth particular limitations.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thespecification illustrate several aspects of the embodiments and togetherwith the description serve to explain the guiding principles herein. Inthe drawings:

FIG. 1A is a diagrammatic view of a container with a floating vent tube;

FIG. 1B is a view similar to FIG. 1 with a floating vent tube at a lowerfluid level;

FIGS. 2A and 2B are views showing various container orientations;

FIG. 3 is a view showing an alternate placement of air vent ports for acontainer;

FIGS. 4A and 4B are views showing accessories for a float supporting anair conduit tube;

FIG. 4C is a view showing an alternate air conduit tube; and

FIGS. 5A and 5B are views according to the prior art showing fluidleakage from a container having no floating vent tube.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

In the following detailed description, reference is made to theaccompanying drawings where like numerals represent like details. Theembodiments are described in sufficient detail to enable those skilledin the art to practice the invention. It is to be understood that otherembodiments may be utilized and that changes may be made withoutdeparting from the scope of the invention. The following detaileddescription, therefore, is not to be taken in a limiting sense and thescope of the invention is defined only by the appended claims and theirequivalents. In accordance with the features of the invention,containers have floating tubes venting interiors to atmosphere toovercome leakage for use in micro-fluid applications.

With reference to FIGS. 1A and 1B, a supply item container 10 for use inan imaging device includes a housing 12. The housing defines an interior14 that contains an initial or refillable supply of fluid, e.g. ink 16.The fluid is any of a variety, but typifies aqueous inks such as thosebased on dye or pigmented formulations. It also represents varieties ofcolor, such as cyan, magenta, yellow, black, etc. The item is useful inmany applications such as inkjet printing, but certainly can be usefulwith other fluids in medicinal delivery, forming circuit traces, foodprocessing, chemical manufacturing, etc.

During use, the volume of ink depletes downward toward a bottom surface18 of the interior of the housing in a direction of gravity G. Thebottom surface is generally flat or inclined to funnel ink out of theinterior. The ink flows to an imaging device by way of a fluid exit port20. An air venting port 22 provides an intake of ambient, recycled orother air to overcome backpressure in the interior 14 that increasesduring imaging operations. The ports are any of a variety but typifycylindrical tubes biased shut with an internal ball and spring (notshown). They are mated with a septum needle 30 from the imaging device.The needle inserts into the ports to overcome the bias of the spring andthe ball slides backward. Upon sufficient insertion, openings in theport and needle are communicated so that a fluidic channel opens betweenthe interior 14 of the housing and the needle. The fluidic channel iseither air or liquid.

Within the interior 14, the air vent port 22 connects to an air conduittube 50. The tube is flexible and floats in the interior. It has aterminal opening 52 that fluidly connects the interior with air fromoutside the housing. A float 60 connects to the tube to suspend theterminal opening 52 above a surface 70 of the volume of fluid. As thevolume of fluid depletes in the interior over time or as an orientationof the housing is altered, the terminal opening is maintained above thesurface of the volume of fluid.

With reference to FIG. 1B, the terminal opening is kept above the fluidas the volume of fluid depletes to a fluid level B from fluid level A(FIG. 1A). (Conversely, the float would rise upon users refilling thecontainer.) While the drop causes the float 60 to drop, it does notcause the float to rotate the terminal opening under the surface 70 ofthe fluid. Rather, the air conduit tube 50 acts as a tether on the floatto prevent this. The interior walls 55 also serve to bound the area oftravel in which the float can maneuver.

In FIGS. 2A and 2B, the terminal opening 52 is kept above the fluid asthe orientation of the housing 12 is manipulated regardless of whetherthe air vent port 22 resides above (FIG. 2A) or below (FIG. 2B) thesurface 70 of the volume of fluid. This mitigates or solves the problemof the prior art where fluid drops 116′ of ink 116 have been observed toleak from a housing 112 at an air vent port 122 as users move thehousing from a proper orientation during use (FIG. 5A) to an alternateorientation (FIG. 5B). With reference to FIG. 3, further embodimentsnote that the placement of the air vent port 22 can change withoutcompromising the venting of the interior of the housing or implicatingfluid leakage. As noted, the air vent port can reside at any of thediscrete positions labeled 22-1-22-6 or at any position along the lengthof any of the walls 55. Its position can be initially beneath or belowthe surface 70 of the volume of fluid as the housing 12 housing isproperly oriented during use to deplete the volume of fluid from theinterior. Similarly, the air vent port 22 can be above or below thefluid exit port 20 as the housing is properly oriented during use.

With reference to FIGS. 4A and 4B, accessories to the float 60 may beused to improve the foregoing notions. First, a float can have acounterweight 61 to produce a moment arm that rotates the float in thedirection of the arrow 1. The weight/rotation technique ensurespositioning the terminal opening 52 in a vertically upright manner. Ofcourse, the weight can be heavier/lighter and/or larger/smallerdepending upon how much torque is needed to cause rotation per a givenset of conditions. Second, the float 60 can be adorned with ahydrophobic membrane 63 that is permeable to air. While attaching themembrane over the terminal opening 52, the air conduit tube stillremains vented to atmosphere and minute drops of fluid are preventedfrom entering the tube and exiting the air vent port as fluid sometimessloshes in the interior during times of handling. An undersurface 65 ofthe membrane can adhere to an exterior surface 67 of the float forproper placement. The membrane is as thin as possible but may define athickness of at least a few mils. Representative membranes contemplatethe use of polytetrafluoroethylene (PTFE) or other materials. Membranesof this type are sometimes referenced as “breather” vents. Withreference to FIG. 4C, minute drops of fluid can be alternativelyprevented from entering the tube 50 by tapering its remote end 69. Inthis way, the terminal opening 52 presents a small front to the interiorof the housing to minimize entry of small drops of fluid, but does nototherwise affect the ability of the tube to vent the housing. Tubediameters of about 0.1 mm are expected in the vicinity of the terminalopening 52.

In any design, the tube 50 attaches to the float, such as by insertionthrough an interior channel 69 of the float. In this way the terminalopening 52 of the tube is made coterminous with the exterior surface 67of the float thereby keeping the terminal opening a sufficient distanceaway from the surface of the fluid but still allowing the membrane tocover the terminal opening while attaching to the float. Alternatively,the terminal opening is positioned only a portion of the way into theinterior channel or positioned to extend well beyond the surface of thefloat to maximize the distance between the fluid and the opening.Alternatively still, the tube is attached to an exterior of the float,not an interior. In any design, the float 60 may have portions 62temporarily or permanently suspended under the surface 70 of the fluid.Either is acceptable so long as the terminal opening remains open.

Regardless of design, common constraints for containers are noted. Forexample, it is expected that the air conduit tube will be formed of amaterial that is compatible with the fluid of the container over alifetime of usage and is flexible to move. Polypropylene is one suchmaterial and is commercial available under the trade name “Tygon.” Alength of the material will vary according to its positioning in theinterior relative to the location of the air vent port, but may be setwith an initial distance of at least two inches to extend across alength of the container. Otherwise, if the tube is too short, anyabnormal orientation of the container might submerge the terminalopening of the tube beneath the surface of the fluid and cause leakage.A diameter of the tube will be largely dictated by the diameter of theair vent port and, in turn, the constraints of the accompanying imagingdevice that is furnishing the atmospheric conditions.

The float 60 is envisioned as cork or low density Styrofoam. As thevolume of the float consumes space within the interior 14 of thecontainer that could be otherwise filled with fluid, a smallervolumetric float is contemplated rather than a larger float to maximizefluid capacity. The float preferably is also of a composition thatavoids absorption of fluid, otherwise its intended function might becompromised. Its shape is any of a variety, but spherical is thelikeliest of candidates. The float 60 will also likely connect direct tothe tube 50, such as by welding, adhesives or mechanical fasteners, orby intermediate structures, such as by connecting rods or wires thathang the tube with its terminal opening in an upward orientation.

The housing itself is any of a variety of containers for holding ink. Itcan typify plastic, glass, metal, etc. It can be recyclable or not. Itcan contemplate simplicity or complexity. Techniques for production arevaried, but blow molding, injection molding, etc. are common techniques.With blow molding, the housing 12 can be made of unitary construction todefine the interior 14. Welding, heat-staking, bonding, dies, etc. arealso envisioned. The materials, construction, shipping, storage, use,etc. of the housing can also focus design criteria on items, such ascost, ease of manufacturing, durability, or other. Its shape is nearlyinfinite. Implicating its selection are good engineering practices suchas contemplation of a larger imaging context in which the housing willbe used. In the design given, the housing is generally elongated fromits back end 39 to its port end 41. The port end inserts forward into animaging device as the back end is pushed upon by users. The shape alsocontemplates seals and septums or the like which may find utility in thedesign at the interface joints between the ports and the imaging device.

The foregoing illustrates various aspects of the invention. It is notintended to be exhaustive. Rather, it is chosen to provide the bestillustration of the principles of the invention and its practicalapplication to enable one of ordinary skill in the art to utilize theinvention. All modifications and variations are contemplated within thescope of the invention as determined by the appended claims. Relativelyapparent modifications include combining one or more features of variousembodiments with features of other embodiments.

1. A container to hold an initial or refillable volume of fluid,comprising: a housing defining a fluid exit port, an air vent port, andan interior to retain the volume of fluid, the interior being properlyoriented during use to deplete the volume of fluid toward the fluid exitport; an air conduit tube having a terminal opening in the interior ofthe housing that is fluidly connected to the air vent port to vent theinterior with air from outside the housing; and a float for buoyantpositioning on a surface of the volume of fluid, the float connecting tothe air conduit tube to suspend the terminal opening above the surfaceso that as the volume of fluid depletes in the interior over time or anorientation of the housing is altered, the terminal opening ismaintained above the surface of the volume of fluid.
 2. The container ofclaim 1, wherein the air conduit tube inserts through an interior of thefloat.
 3. The container of claim 2, wherein the terminal opening of theair conduit tube is coterminous with a surface of the float.
 4. Thecontainer of claim 1, further including a hydrophobic membrane attachedover the terminal opening of the air conduit tube, the membrane beingpermeable to said air.
 5. The container of claim 4, wherein anundersurface of the hydrophobic membrane is adhered to an exteriorsurface of the float.
 6. The container of claim 1, wherein the air ventport of the housing resides beneath the surface of the volume of fluidas the housing is properly oriented during use to deplete the volume offluid from the interior.
 7. The container of claim 6, wherein the airvent port is located above the fluid exit port of the housing as thehousing is properly oriented during use to deplete the volume of fluidfrom the interior.
 8. The container of claim 1, further including acounterweight on the float to position vertically upright the terminalopening of the air conduit tube.
 9. The container of claim 1, whereinthe housing is of unitary construction being blow molded to define theinterior.
 10. The container of claim 1, wherein the air conduit tubeextends for a length of at least two inches in the interior.
 11. Thecontainer of claim 1, wherein the float includes cork.
 12. The containerof claim 1, wherein the float includes Styrofoam.
 13. The container ofclaim 1, wherein the air conduit tube tapers at a remote end thereof.14. The container of claim 13, wherein the terminal opening has adiameter of about 0.1 mm.
 15. A container to hold an initial orrefillable volume of fluid, comprising: a housing defining a fluid exitport, an air vent port, and an interior to retain the volume of fluid,the interior being properly oriented during use to deplete the volume offluid toward the fluid exit port in a direction of gravity; an airconduit tube having a terminal opening in the interior of the housingthat is fluidly connected to the air vent port to vent the interior withair from outside the housing; and a float for buoyant positioning on asurface of the volume of fluid, the float connecting to the air conduittube to suspend the terminal opening above the surface so that as thevolume of fluid depletes in the interior over time or an orientation ofthe housing is altered, the terminal opening is maintained above thesurface of the volume of fluid, wherein the air conduit tube insertsthrough an interior of the float so that the terminal opening residescoterminous with a surface of the float and a hydrophobic membraneattaches over the terminal opening, the membrane being permeable to saidair.